Abstract: Compounds useful for associating with nanoparticle or microparticle emulsions to obtain magnetic resonance images permit control of the relaxivity of the signal and readily associate with the particulate components.

Abstract: Dense star polymers having terminal group densities greater than conventional star polymers exhibit greater and more uniform reactivity than their corresponding conventional star polymers. For example, a third generation, amine-terminated polyamidoamine dense star polymer prepared from ammonia, methyl acrylate and ethylenediamine has 1.24.times.10.sup.-4 amine moieties per unit volume (cubic Angstrom units) in contrast to the 1.58.times.10.sup.-6 amine moieties per unit volume contained by a conventional star polymer. Such dense star polymers are useful as demulsifiers for oil/water emulsions, wet strength agents in the manufacture of paper, and agents for modifying viscosity in aqueous formulations such as paints.

Abstract: A method for altering the reproductive function of mammals by administering a pharmacologically effective amount of certain fluoroalkyl-substituted organosilicon compounds. As a means of illustration, one can orally or parenterally administer from 1.0 mg. to 100 mg. per kilogram of body weight (either as a single dose or as a daily dosage over a period of time) of an organosilicon compound of the formula ##STR1## thereby rendering the subject (either a male or female mammal) infertile.